Sanitary napkin

ABSTRACT

A sanitary napkin comprising a plurality of layers of absorbent material, at least one barrier sheet of liquid repellent material interposed between said absorbent layers, said sheet being completely liquid repellent, a waterproof strip, and an outer wrapper.

United States Patent Appl. No. Filed Patented Assignee Priority SANITARY NAPKIN 2 Claims, 7 Drawing Figs.

US. Cl 128/287 Int. A61f 13/16 Field 01 Search 128/287,

[56] References Cited UNITED STATES PATENTS 1,643,615 9/1927 Williams 128/290 1,843,037 1/1932 Mathey 128/290 1,863,333 6/1932 Heitmeyer 128/290 2,464,640 3/1949 FOUIHESS 128/290 2,566,325 9/1951 Ganz... 128/290 Primary Examiner-Charles F. Rosenbaum Attorney-Wenderoth, Lind & Ponack ABSTRACT: A sanitary napkin comprising a plurality of layers of absorbent material, at least one barrier sheet of liquid repellent material interposed between said absorbent layers, said sheet being completely liquid repellent, a waterproof strip, and an outer wrapper.

PATENTEDUBHZIQH I $612,054

SHEET 2 OF 2 0 Fly. 4 ll 8 9 9b 80 TAMIL) MA'ISUDA 'LSUTOMU OKAMURA NOBU KONISHI SANITARY NAPKIN This invention relates to an improved sanitary napkin.

The main object of this invention is to provide a sanitary napkin of an improved construction which contains one or three barrier sheets of liquid repellent material to utilize the absorbing capacity of the absorbent layers effectively. Another object is that of providing a sanitary napkin construction which makes it possible to attain the foregoing main object in a commercially practicable manner. Other specific objects and advantages of the invention will become apparent from the following description and the accompanying drawings.

Examples of sanitary napkins in accordance with this invention are shown in the accompanying drawings, in which:

FIG. I is a plan view of a sanitary napkin embodying features of this invention;

FIG. 2 and FIG. 3 are sectional views of FIG. 1, taken on the lines 2-2 and 33, respectively;

FIG. 4 and FIG. 5 are sectional views respectively corresponding to FIG. 2 and FIG. 3, which illustrate another embodiment of this invention; and

FIG. 6 and FIG. 7 are sectional views respectively corresponding to FIG. 2 and FIG. 3, which illustrate a further embodiment of this invention.

Referring now to FIGS. 1 to 3, the body portion of the sanitary napkin embodying this invention comprises two layers 8 and 8a of absorbent material such as cotton, creped tissue paper, or other well-known absorbent equivalents. Between the layers 8 and 8a there is interposed a barrier sheet 9 of liquid repellent material which is preferably half as long as the layers. The barrier sheet consists of thin films of synthetic resins such as polyethylene, polypropylene and the like, which do not form a gel upon contact with'liquid and are completely liquid repellent; waterproof papers or tissue papers treated with a suitable water-repellent such as aluminum acetate, wax emulsions, wax emulsions plus aluminum salts, wax solution in organic solvent, polymerized silicone resins, organosilicone polymers, long chain pyridinium compounds, wax zirconium acetate emulsions, oil, etc.; and papers or tissue papers coated or laminated with said thin films of synthetic resins.

The two absorbent layers 8 and 8a and a waterproof strip 10 placed under the layer 8a are enclosed in an outer wrapper 11 which may consist of a conventional material used as covers for sanitary napkins, such as woven or nonwoven fabrics of rayon, cotton, or other suitable fibrous materials. Although the waterproof strip 10 which may consist of a well known and conventional material is approximately as wide as the absorbent layers as shown in FIG. 2, it may be wider than the latter.

Referring to FIGS. 4 and 5, the body portion of thesanitary napkin of this invention comprises three layers 8, 8a, and 8b of absorbent material. A barrier sheet 9 is placed centrally between the layers} and 8a, and two barrier sheets 9a and 9b are interposed separately between the layers 8a and 8b whereby the barrier sheet 9 overlaps at the edges thereof partly the barrier sheets 9a and 9b with the layer 8a as intermediate, as illustrated in FIG. 4. It is desirable that the three barrier sheets 9, 9a, and 9b have each an approximately onesixth to one-third length of the absorbent layers. Under the absorbent layer 8b a waterproof strip 10 is placed. The main body so obtained is enclosed in an outer wrapper l 1.

FIGS. 6 and 7 are longitudinal and cross sections of a sanitary napkin of this invention, respectively, in which napkin the central barrier sheet 9 is disposed under the intermediate absorbent layer 8a and the side barrier sheets 9a and 9b above the same layer 8a. When liquid is applied to the surface of a sanitary napkin in accordance with this invention, it penetrates downwardly at the point of application to the barrier sheet whereupon it is caused to spread laterally and longitudinally along the barrier sheet. The liquid overfiowed from the barrier sheet penetrates again into the absorbent layer below. Thus the absorbing capacity of the absorbent layers in the sanitary napkin of this invention is utilized effectively, by the action of the barrier sheets.

What is claimed is:

1. A sanitary napkin comprising three layers of absorbent material, one barrier sheet of liquid repellent material interposed centrally between the upper and middle absorbent layers, two barrier sheets of liquid repellent material interposed separately between the middle and lower absorbent layers so that the central barrier sheet overlaps at its edges partly the two side barrier sheets with the middle absorbent layer as intermediate, said three barrier sheets being completely liquid repellent, a waterproof strip placed under the lower absorbent layer, and an outer wrapper.

2. A sanitary napkin comprising three layers of absorbent material, one barrier sheet of liquid repellent material interposed centrally between the middle and lower absorbent layers, two barrier sheets of liquid repellent material interposed separately between the upper and middle layers so that the two side barrier sheets overlap at their inside edges partly the central barrier sheet with the middle absorbent layer as intermediate, said three barrier sheets being completely liquid repellent, a waterproof strip placed under the lower absorbent layer, and an outer wrapper. 

1. A sanitary napkin comprising three layers of absorbent material, one barrier sheet of liquid repellent material interposed centrally between the upper and middle absorbent layers, two barrier sheets of liquid repellent material interposed separately between the middle and lower absorbent layers so that the central barrier sheet overlaps at its edges partly the two side barrier sheets with the middle absorbent layer as intermediate, said three barrier sheets being completely liquid repellent, a waterproof strip placed under the lower absorbent layer, and an outer wrapper.
 2. A sanitary napkin comprising three layers of absorbent material, one barrier sheet of liquid repellent material interposed centrally between the middle and lower absorbent layers, two barrier sheets of liquid repellent material interposed separately between the upper and middle layers so that the two side barrier sheets overlap at their inside edges partly the central barrier sheet with the middle absorbent layer as intermediate, said three barrier sheets being completely liquid repellent, a waterproof strip placed under the lower absorbent layer, and an outer wrapper. 